1. Field of the Invention
This invention relates to containers, particularly to such containers that can be readily self sealed, and that do not require the moistening of dry adhesive layers, or the additional production, mounting and subsequent removal of protective release liners, or the use of adhesive tape for fastening.
2. Description of Prior Art
A conventional system to seal envelopes, bags, boxes, packaging, etc. uses a dry glue coating that needs to be moistened to promote adhesion of the surfaces involved. Depending on the scale and nature of each task, this moistening is normally achieved by different means, including the use of wet sponges, roll-on bottles with water, and the actual licking of the dry glue with the user""s tongue. Regardless of the means used, the need to moisten a dry adhesive coating is precisely the first disadvantage of this system. Also the implementation of this system to seal envelopes is highly challenged by the high temperatures used by roller friction printers which in many cases cause an undesirable premature fastening of the envelope.
Other systems involve the use of heat, and/or delamination of different coatings of adhesive, with the inherent disadvantages that such steps entail. An example of this system is U.S. Pat. No. 3,877,630 to Silver for a xe2x80x9cMethod and blank for forming a package within a wrappingxe2x80x9d. In recent years, the inconveniences of these archaic systems have prompted different attempts to create a more practical solution, but the success of these attempts has been very relative, since new inconveniences are created in the process.
One of these systems requires two opposite coatings of dry glue (normally rubber cement like) that when contacting one another, the envelope, packaging, box etc. is sealed, eliminating thereby the need to moisten the coating. These are some disadvantages of this system:
1) A higher cost is apparent, since two coatings of glue are necessary.
2) These coatings are exposed at all times, risking the good bonding quality of the glue.
3) The impediment to feed envelopes through machines, such as printers, since the glue and the parts of said machines will disturb each other.
4) The piece must remain unfastened before its use, occupying therefore more shelf or floor space during packaging, storage and display.
Another system uses a pressure sensitive adhesive coating on one of the surfaces that need to be fastened. This pressure sensitive coating is protected with a paper, plastic or synthetic liner carrying a release substance before its use. An example of this system is an envelope manufactured and marketed by Mead Corp. of Dayton, Ohio, under the name of Press it-Seal it(trademark) (Product#43100 75024.)
This system does eliminate the need to moisten the adhesive coating, yet it has its own significant disadvantages:
1) There is an obvious higher cost of production, since foreign parts and additional production steps are required.
2) The presence of this foreign liner may prevent the capability of envelopes and other flat objects to be fed through printers or other machines.
3) The user needs to incur in the additional steps of peeling and disposing of this foreign liner.
Some other examples of this system, having the same disadvantages include: U.S. Pat. No. 3,130,895 to Davis for a book mailer; U.S. Pat. No. 3,306 521 to Giacovas for self sealing paperboard cartons; U.S. Pat. No. 5,499,757 to Back for a tamper-evident envelope which proposes as an alternative embodiment, the use of the pressure sensitive adhesive coupled with the release liner and additionally, having said arrangement mounted on the two surfaces that are being connected, which aggravates the aforementioned disadvantages; U.S. Pat. No. 5,722,585 tp Redl, which discloses the use of a protective strip in cooperation with an adhesive strip, to seal a box after the box has been closed using a tongue-and-slit mechanism. The operability of this system appears questionable, or at least its functionability is highly deficient. Since the patent does not disclose the protective strip""s properties, and the removal of the protective strips must me performed in a lateral fashion, being trapped between the cover and the flaps, two scenarios must be considered, and both scenarios present problems:
1) if the protective strips do not fastenxe2x80x94however lightlyxe2x80x94to the adhesive strips, it will be very difficult to mount them, and even more difficult to keep them in place.
2) if the protective strips do fastenxe2x80x94however lightlyxe2x80x94to the adhesive strips, pulling them out laterally, as disclosed will be extremely difficult, if not impossible, since the necessary direction of removal will have to be of a frontal nature, which is prevented by the cover.
U.S. Pat. No. 4,072,264 to Kranz discloses a duplex envelope that in one of its double aspects requires a removable release liner to protect a coating of pressure sensitive adhesive entailing additional expenses and impracticalities.
U.S. Pat. No. 4,738,391 to Wiseman discloses an envelope that can be temporarily or permanently sealed. To that end, Wiseman proposes two procedures that make the product somewhat complicated and expensive, as depends on both systems already discussed: a) the need to moisten a dry adhesive coating; and b) the need to use removable release liners.
U.S. Pat. No. 5,429,576 to Doderer-Winkler discloses a reusable envelope that needs a removable release liner to protect a coating of adhesive on a flap, and then a protective strip of tape on the body of the envelope to permit the temporary sealing of the envelope, so it can be repeatedly used. These multiple and complex steps suggest that this product is very expensive to manufacture.
U.S. Pat. No. 5,474,229 to Shimazaki proposes a stack of pressure sensitive adhering envelopes, having on the back of each flap a coating of release, and on the front a coating of adhesive, so that when the envelopes are stacked with the flaps open, the adhering interface between the pressure sensitive adhesive and the release is not permanent and each envelope could be sealed without having to moisten the adhesive.
The following are problems and limitations of this system:
1) The need to package and sell the envelopes in quantities. Individual envelopes could not be marketed. Or to be marketed, a release liner must be used, which defeats the purpose of Shimazaki""s patent.
2) The absolute need of having the envelopes in an open condition, prior to their final use, occupying thereby more shelf an/or floor space.
3) The impossibility to feed them through a printer, copier or any other machine.
4) A removable release liner needs to be applied to the flap of the bottom envelope, to protect it.
U.S. Pat. No. 5,711,477 to Jenkins discloses a sift proof carton that has multiple beads of adhesive. The main disadvantage of this method with respect to the present invention is that it is restricted to industrial use, as the application of the adhesive is performed during the packaging process. In other words, the box can not be built and stored for posterior use, as the adhesive beads are exposed at all times until sealing occurs.
In accordance with the present invention, a self sealing container comprises a first, second and third surface sections; applying one or more layers of adhesive to the first and/or second surface sections; applying one or more layers of a release substance to the first and/or second surface sections, in such a manner that the adhesive substance layer(s) face the release substance layer(s) on the opposite section, and then positioning of the third section, free of any substance between the first and second sections to seal the container.
The following are objects and advantages of this invention:
a) to provide a container which eliminates the need to moisten coatings of dry glue to seal it, and avoid all the disadvantages of this system;
b) to provide a container which eliminates the need to use opposite coatings of adhesive to seal it and avoid all the disadvantages of this system;
c) to provide a container which eliminates the need to use foreign strips to protect adhesive coatings, to seal it; and all the disadvantages that this system entails, like higher production costs, that naturally translate into higher retail prices, as this foreign strip must be produced separately, and then affixed to the product; and yet another object is to eliminate the need to remove and then discard this foreign strip by the end user;
d) to provide a container that permits an efficient and practical packaging system, in individual or multiple quantities;
e) to provide a container that makes evident any tampering with its sealing;
f) to provide a container whose manufacturing is economical and cost effective;
g) to provide a container that can be readily sealed, without having to use adhesive tape or any other fastening means;
h) to provide a container that can be readily sealed, without having to use heat;
i) to provide a container that can be temporarily closed prior to a more permanent sealing.
j) to provide a container, embodied as an envelope which can be easily fed thorough any type of personal, commercial or industrial printers.
202 fastener layer
204 optional and alternative lower strength fastener layer
206 fastener inhibitor layer
207 container